Method and apparatus for translating sound wave variations



BEST AVAILABLE o y June 8, 1926.

T. W. CASE METHOD- AND APPARATUS FOR TRANSLATING SOUND WAVE VARIATIONSFiled Nov. 2, 1923 BEST AVAILABLE COP:

Patented June 8, 1926.

UNITED STATES PATENT QFFECE.

THEODORE WILLARD CASE, OF AUBURN, NEW YORK, ASSIGNOR TO CASE RESEARCHLABORATORY INCORPORATED, OF AUBURN, NEW YORK, A CORPORATION.

METHOD AND APPARATUS FOR TRANSLATING SOUND WAVE VARIATIONS.

Application filed November This invention relates to certainimprovements in method and'apparatus for translating sound-wavevariations into corresponding variations of an electric current, which 6latter variations may be used or translated as desired. Or perhapsdifferently stated, the invention relates-to a method of apparatus forproducing variations of an electric current in accordance with orcorresponding to sound wave variations.

The main object-of the invention is to produce a highlysensitiveinstrument that will intensify the sound eflect and accurately translatesound waves into corresponding va- 1 riations of electric current, whichlatter variations may be re-translated with or without, amplification,and with practically perfect quality. r -A further and more specificobject resides in the eliminationof-distortion and foreign noises whichmight result from sympathetic diaphragm vibration, or other causes, andwhich efi'ect'the sound waves to be translated or their translation, andreference is hereby made to my co-pending application Serial No. 652,281filed July 18th, 1923, upon gas-thermo microphone, and which describesand claims the broad subject matter disclosed herein, and to myapplication Serial No. 665,136. filed September 27th, 1923 uponmicrophone, and which latter application discloses the broad subjectmatter disclosed herein, and the claims of which are restricted to. theadjustable opening within 85 which the member that varies its resistanceto the passage of an electric current in accordance with its temperatureis positioned.

The specific subject matter described and claimed herein relates to'th'euse of a specific gas, viz: hydrogemwhieh is highly eflicient andpeculiarly adapted for the purposesof this invention due to variouscharacteristics, as for instance, its comparatively great coolingquality.

In the drawings 2- Figure 1 'is a diagrammatic illustration of theinvention with the gas chamber shown in section.

Figure 2 is a section on line 2-2, Fig- 60 are 1.

Figpre 3 is a front elevatlon of the gas cham er.

- Figure 4 is a view similar to Figure 2,

but in which the gas chamber has a circular 2, 1923. Serial No. 672,324.

opening as distinguished from a somewhat rectangular one, and is takenon line 44, Figure 5.

Figure 5 is a horizontal section thru-the gas chamber illustrated inFigure 4. The invent-ion, as shown, comprisesa substantially fiat disk-1 which may perhaps preferably be of circular form and is provided withan opening 2 illustrated in Figures 1, 2 and 3, as of substantiallyrec-j tangular form, and in Figures 4 and 5 as of substantially circularform, altho the opening may be of various and many forms, and I do not,therefore, restrict myself to any shape, size or form of opening.

. Within this opening is arranged a shortwire 3 formed of a materialthat varies its electrical resistance in accordance withits temperature,and the opposite-ends of this wire -3 are connected in circuit with. thepositive and negative sides respectively; of a variable source ofpotential, such as the battery 4, any suitable means ofwellknownconstruction being provided for-"cf fecting desired variations ofthe source of potential utilized for heating thewire 3.' VVit-hin thiscircuit may be positioned the. primary 5 of a transformer, the secondary6 of which may be connected to suitable amplifying means or directly toany suitable translating means-such as the tele-. phone receivers 7.Preferably the wire 3- is of very small diameter, as'for illustration,plus or minus .00001, and is in the form of a coil or low pitch spiral,as indicated, and is arranged in the opening 2-' in the disk 1, and forillustrative purposes this opening 2 may be about onehalf an inch longand one-quarter inch wide, and the wire 3' in its spiral form may beapproximately one-quarter inch long so as to fit within the openingwithout contact therewith. However, the opening may be of variousshapes, as circular, and the wire instead of being spiral in form, maybe of varied forms, as straight, and more than one wire 3 may be used ifdesired. The disk 1' may, as shown, be formed with an annular flange -8penetrated by an inlet pipe 9 adapted to carry hydrogen gas underpressure from any suitable source of supply as blower --10 or the usualtank for containing such gases under pressure, and the rate 9. flow ofhydrogen open and part of the hydrogen gas may escape the'rethrough. Theremainder of the hydrogen gas entering the gas chest --12 from the pipeesczr-pes through the opening -.2 around tliewire' 3 and tends to coolthe wire at all tunes. Fhe

wire-may be formed of any suitable iiiziterie-l that varies itsresistance to the passage of an electric current in accordance-with itstemperature,and altho various substances may be used, I have foundplatinum suit-' able; tor the purpose.

: Pla'cin the filament in :in opening of? desired size;- such as theopening ''2- intensifies the sound effect resultant flOlHfil-IQ use(if-the a: pa ratns and Withoutdistortion.

Bfieforrfiblj thedi sk=1 is used as the front? 01* the apparatus, and istoward the speaker or the sound waves which it is desired totranslate,as in th i's'position the sound Waves td-he translated are coming indirection substantially" opposite to the direction of the movement: ofthe hydrogen gas escaping through the opening-' 9'r', and acting tocool"- the spiral Wire --3'-. This positioningiof' the instrument isnot-, h-o'wever, essential, althe'my present: experience leads me" tobelieve that a more advantageous result is obtained intha tmanner. v

I have found that it is-Very desirable and adyantageous'in an apparatusof this character to provide means for readily and easily varying thesize of the opening 2 in which the resistance element 3- is positioned,and in Figures'Q- and 3 I have hill-F trated for this purpose slides or7 plates "-13 and 14- positioned upon opposite sides of the opening-2'-, and slida-ble ac'ross'the opening to restrict or enlarge its area;as ma be desired. Tl1ese sli:des or shutters they be supported in anysuitable way'for adjustment, as described, and for that: purpose I: haveshown than carried and supported-by studs' 1'5" and- '16'-- respectivelywhich extend thru slots: 17'- and '1'-8 res 'e'c'tively in the disk-1for engagement with locking n'uts -19- and 20 respectively for-securingthe' slides in afiy -desired-posi-ti'enof adjustment for producing thedesired area of opening or gas passage;

These sliut-ters 13' and 1%, as shown, are'guidedfinchannel' yvaysformed by' the undercut members- -21',--22-,

BEST AVAILABLE COPi 23 and 24-- secured to the disk -lto perm-itslidingmovement of the shutters when the nuts 19 and 20 are loosened,and to guide the shutters in their adjusting movement. I

In Figures l and 5 the disk- -1 is shown as provided with a circularopening -2 and the shutters ,5 and-""26 are each formed withsemi-circular recesses so that when the shutters are adjusted in onerelative position they form a substantially circular opening, the size0% Whichc'an be varied by sliding" the shutters eienefito ward or fromeach other, and fo tlns pur posethe adjacent ends of the sl t-utter"s'have a portion of their thickness cut away that one may slide upon theother, Iirotheif words, the inner endsof the s11utt1rs='25-" and 26 areeach preferably of siibst-a n tial ly one-hal=f the thickness of the'bederfi the shutter, as illustrated at 28-, and these parts are op ositelydisposed sothat one may s'l i'de'i'ipon 'the other, and jointly theyconstitute a" thikiknes's "s'n stan'ti'a-l'ly equal to thethicline'sso'ftlie'bed'y of eithr o-t the shutters 25 and @hviously, relative slidingmovements of the plates 25 and 2'6' vary" somewhat the shape of the oening-+2 from an exact circular form andthe s'tr ucture I" have shown ispurely il-l' ustrhtive'oui ameans for varying the sizeof an o enin whichat one particular adjnstment iscii oular, and various and' many otherstrue tures' may be substituted for that' shbvin; and Well knownconstructions, suelr a camerashutte'i" may be utilized for adjustin'gthe size of the opening 2'-'-,' the structures that I have sl1ovvn"hei'ng urely illi'1s trative of means for acoomplishingthis de sirable'result of an adjustmentof this hydrogen gas passage- Without limitationto the shape or size of the opening, as wide variation is possible inthe shape, form (t-nil size of the'opening and the meahs forzrd'justin-g the area of the samewithin the scope of the appended claims: Asber'or stated, this specific adjustment feature isthe subject matter ofthe claims of a copendi'ngapplication.

It will be obvious that my invention sofar as structure and arrangementof parts is concerned may take various and many forms, and that so firas the subject matter here is concerned, I do not desire'to re strictmyself to any form, shape or construction of apparatus,asvariouschangesmay be made without departing from the invem' tion asset forth in the appended clai ms 1. In an apparatus of the classdescribed, the combination with a passa e'way for a forced current ofhydrogen, and cans for causing hydrogen under pressnre-to'fi'ow throughsaid passageway of a? member that varies its electrical resistance inaccordance with its temperature exposed to the hydrogen escaping throughsaid passageway.

2. In an apparatus of the class described, means for producing a forcedcurrent of hydrogen, and a member which Varies its electricalconductivity in accord ance with its temperature exposed to the forcedcurrent of hydrogen and means for heating said member.

3. In an apparatus of the class described, a chamber for hydrogen gas,means for supplying hydrogen gas under pressure to said chamber, anoutlet from said chamber and a member that varies its electricalconductivity in accordance with its temperature exposed to the hydrogenescaping through said outlet.

4. In an apparatus of the class described, a chamber for hydrogen gas,means for supplying hydrogen gas under pressure to said chamber, anoutlet from said chamber, a member that varies its electricalconductivity in accordance with its temperature ex- 3513? AVMLAB'LE COP!posed to the hydrogen escaping through said outlet, and means forheating said member.

5. In an apparatus of the class described, a hydrogen chamber, means forsupplying hydrogen under pressure to said chamber, an outlet from saidchamber, a member that varies its electrical conductivity in accordancewith its temperature arranged in said outlet, and means for heating saidmember.

6. In an apparatus of the class described, a hydrogen chamber, means forsupplying hydrogen under pressure to said chamber, an outlet from saidchamber. a member that Varies its electrical conductivity in accordancewith its temperature arranged so as to be exposed to the hydrogen whichpasses through said outlet in said outlet, and said chamber having awall formed of a porous member.

In witness whereof I have hereunto set my hand this 18th day of October1923.

THEODORE WILLARD CASE.

